Work-holding device having plungers actuated by hydraulic fluid composed of a fusible alloy



1 1959 R. R. BLAZEK 2,882,771

WORK-HOLDING DEVICE HAVING PLUNGERS ACTUATED BY HYDRAULIC FLUID COMPOSED OF A FUSIBLE ALLOY Filed June 22, 1956 2 Sheets-Sheet 1 IN V EN TOR.

RONALD RBLAZEK Y T OENEXB.

April 21, 1959 R. R. BLAZEK 2,882,771

WORK-HOLDING DEVICE HAVING PLUNGERS ACTUATED BY HYDRAULIC FLUID COMPOSED OF A FUSIBLE ALLOY Filed June 22, 1956 2 Sheets-Sheet 2 INVENTOR. I RONALD R. B LAZEK A TTORNEXS- United WORK-HOLDIN G DEVICE HAVING PLUNGERS ACTUATED BY HYDRAULIC FLUID CONIPOSED OF A FUSIBLE ALLOY Ronald R. Blazek, Cleveland, Ohio Application June 22, 1956, SerialNo. 593,281

6 Claims. (Cl. 81-38) v This invention relates as indicated to a novelworkholding device, and more particularly to a clamp or vise especially adapted securely to hold irregularly shaped objects during the performance of machining operationstates Patent I tion and an opposed clamping member provided with a plurality of plungers adapted to engage the work and automatically to conform to the corresponding contour thereof. Such type of clamp, while of advantage under certain circumstances, is nevertheless not entirely satisfactory when the object to be held is of irregular or uneven contour on each of its sides to be engaged by the clamping means. Moreover, it is frequently desired to hold the article being clamped in a particularly oriented position and to ensure that like articles subsequently gripped will be identically positioned.

An important object of my invention is accordingly to provide novel work-holding means including opposed clamping units, each of which is adapted automatically to conform to the surface contours of the article engaged thereby.

Another object is to provide such device wherein one such unit may be semipermanently rigidified to support the article being clamped against wobbling or other movement and to ensure exactly similar placement of like objects subsequently secured thereby.

Other objects of the invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawing setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawing:

Fig. 1 is a top plan view of novel clamping means embodying the principles of my invention;

Fig. 2 is an end elevation of such device;

Fig. 3 is a side elevation of such device;

Fig. 4 is a longitudinal section on an increased scale taken on the line 4-4 on Fig. 1; and

Fig. 5 is a detail view of one of the clamping units. partly broken away better to show the arrangement of the clamping fingers or plunger-s.

Referring now more particularly to such drawing, the embodiment of my invention there illustrated comprises a base 1 adapted to be mounted upon a work bench or like support and having a horizontally disposed transverse way 2 bolted thereon. way is rigidly mounted an upwardly extending metal block 3 having a backing plate 4 bolted thereto. An opposed block 5 with a backing plate 6 is mounted on the Way 2 for reciprocation therealong toward and away from the block 3. A screw 7 is threadedly engaged in an upstanding bracket 8 with its end freely rotatably-in; terengaged with the back plate 6 of block 5 so that such plate and block may be thus adjustably positioned relative to the block 3.

As best shown in Figs. 4 and 5, each of such blocks plurality of cylinders such. as 9 and 10 respectively in which opposed clamping fin-' and 4 is drilled to provide a gers 11 and 12 are fitted for reciprocation toward and away from each other. The cylinders 10 are provided with O-ring seals such as 13, 14 and 15, and a check valve inlet 16 is provided for introducing hydraulic fluid to such cylinders, the latter being interconnected as by means of lateral ports 17. The individual cylinders are closed as by means of plugs 18 which are further retained in place by the backing plate. The cylinders 10 of block 5 are filled with hydraulic fluid when the fingers 12 are partially retracted into such cylinders as shown'in Figs. 4 and 5, for example. Thus when pressure is exerted upon the outer end of any one of such pistons or fingers 12 to force such finger inwardly, another finger or fingers must necessarily simultaneously move outwardly. An irregularly shaped workpiece engaged by the rows of fingers 12 will accordingly cause retraction and extension of appropriate fingers to conform to the contour engaged thereby.

If the other side of an irregularly shapedworkpiece were thus similarly simultaneously engaged by the ends of the clamping fingers 11, the cylinders 9 being likewise partially filled with hydraulic fluid such as oil, it is apparent that such fingers 11 would be retracted and extended to conform to the opposed profile. The clamp ing action of the two opposed sets of fingers, however, would be inadequate since it would still be possible to turn or wobble the workpiece with certain fingers of one set being retracted while the directly opposed fingers of the other set would be correspondingly extended. For this reason, instead of employing the usual hydraulic fluid within the cylinders 9 of block 3, I provide an easily fusible solid material M such as Woods metal or Roses metal (these being commercially available low melting alloys of bismuth, lead and tin in the case of Roses metal, and a similar composition with inclusion of cadmium as Woods metal) and I preferably provide an insulated heating coil 19 within the backing plate 4 effective quickly to melt the alloy thus employed when desired. It will thus be understood that the alloy used, though solid at ordinary room temperature, can easily be fused somewhat above such temperature. The pistons 11 are provided with O-ring seals 20 and the pistons 12 with similar seals 21.

The operation of my new work-holding device may now readily be understood. The irregularly shaped workpiece will be placed between the opposed clamping fingers 11 and 12 and the screw 7 turned until the workpiece is firmly engaged by the ends of the opposed fingers, the fusible metal M in cylinders 9 being kept in a molten condition. If any individual clamping finger 11 or 12 fails to engage a portion of the workpiece surface, it may be fully extended from its particular cylinder to the extent permitted by the piston shoulder. When the workpiece has been thus engaged and positioned to suit the operator, the block 3 and the metal M Patented Apr. 21, 19.59

Adjacent one end of such.

arepe'rrriitte'd*to edofor 'ai'e chilled as by pouring water thereover to solidify'such metahso'that'fingers 11 are thereafter rigidly supported against the contour of the workpiece engaged thereby. 'Not only is the workpiece ndw firmly and securely"cla'niped "for performance of a machining'operation thereon, butalso"when" such workpiece'is subsequently released by reve'rserotation of the screw 7 andTemove'd, similar work pieces of identical content may now be-substituted'therefor'for performance of like operations thereon and "will he -clampe'd and identically positioned through engagement of 'the"adju'sted fingers 11 which in effect now serve'also asa jig tar-fixture. -Of-course, when ditferenflobiects 'are'to-be clamped, the fusible metal M will simply beinelted through heat from the electricheatingcoil iyto' permit readjustment ot-the-fingers '11. I v r '(Jther medes of applying the 'a'rinciple "ofthe' invention may be employed, change being nia'de as"regards the details desc'ribe'd, provided fthe features stated in any-of the follo'wing 'claims orthe equiva'lent of "such beemp1oyed. I

-1 therefore particularly point-out and distinctly claim as my invention:

1. A work-holding device comprising two opposed sets of plunger assemblies, ends or saidplungers of each set protruding toward the other-to engageand "grip a workpiece therebetween, hydraulicfliiid 'manifolded to the inner ends of-said plungers of one'of said 'setsfand a-molten easily fusible alloy manifolded'to-the inner ends of said plungersof the-other of saidsets.

=2. The device of claim 1 wherein one of said sets is mounted for movement bodily toward and away from the-other of "said sets, and said-plungers of each set are normally only partially extended when uniformly arranged. v

3. A work-engaging means comprising aplurality of parallel cylinders, plungers fitted for reciprocation therein and-extending therefrom, means interconnecting said cylinders to manifold the same, and analloy, solid at ordinary room temperature buteasily fusible somewhat above such ternperaturqfilling said-cylinders with at least certain of said plungers partially retracted therein.

4. The work-engaging means of claim 3 including heating means operable to melt said alloy.

5. A work-holding device comprising two opposed sets of plunger assemblies, ends of said plungers of each set protruding toward the other toengage and grip a workpiece therebetween, and hydraulic fluid manifolded to the'inner ends of said plungers of each set, said fluid in at'leastone of said sets being an alloy, solid at ordinary room temperature but easily fusible somewhat above such temperature.

6. A clamping device comprising a way, a block fixedly secured thereon, a secondblock slidably mounted on said way for reciprocation therealong toward and away from said first block, screw means operative thus adjustably to position said second block relative to said first block, a plurality of cylinders in each block parallel to said Way and opening through-the respective='opposed faces of said blocks, said cylinders in I each block being manifolded in respective closed systemsJpi'stons-in said cylinders extending through such openings, said pistons having shoulders elfective to prevent complete emergence from their respective cylinders,hydraulic' fluid filling said cylinders with said pistons at least partially retracted therein, the hydraulic-fluid in'said'cylinders of said first block being an easily fusible alloy, 'and said device incorporating electric heating means operable to heat said first block and thus melt the alloy contained therein.

' References Cited in the fileof this-patent UNITED STATES PATENTS 995,537 Hertner et al. s June 20,4911

1,453,176 Perrine A r. -24, 1923 FOREIGN PATENTS 76,279 Austria Apr. -25, 1919 165,454 Australia 'Mar. 11, 1954 639,696 Great Britain July'5, 11950 

